Hot-gas reciprocating engine and refrigerator or heat pump operating on the reversed hot-gas reciprocating engine principle



y 1955 A J J. LAMBEEK 2,709,334

HOT-GAS RECIPROCATING ENGINE AND REFRIGERATOR 0R HEAT PUMP OPERATING ON THE REVERSED HOT-GAS RECIPROCATING ENGINE P INCIPLE Filed July 28, 952 I Adrioan Jon Uurrioun Lumbeek AGENT HOT-GAS RECIPROCATING ENGINE AND RE- FRIGERATOR OR HEAT PUMP OPERATING ON THE REVERSED HOT-GAS RECIPROCAT- IYG ENGINE PRINCIPLE Adriaan Jan Jurriaan Lambeek, Dordrecht, Netherlands,

assignor to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application July 28, 1952, Serial No. 301,207

Claims priority, application Netherlands September 5, 1951 7 Claims. (Cl. 60-24) This invention relates to hot-gas reciprocating engines and refrigerators or heat pumps operating on the reversed hot-gas reciprocating engine principle, of the kind comprising a crank case and means to convey supplementary gaseous medium from the crank case to the working space.

A hot-gas engine or a refrigerator or heat pump operating on the reversed hot-gas engine is to be understood to be an apparatus in which a gaseous or vaporous the working medium converts heat into mechanical energy. However, if the working medium is compressed at a higher temperature than that at which it expands as occurs in a refrigerator or heat pump, mechanical energy is supplied to the apparatus to obtain a transport of thermal energy from a lower level to a higher level.

Since the crank case of such an engine or other apparatus contains contamination (liquids such as water and lubricant) and since for satisfactory and economical operation of the apparatus, efforts are made to render the supplementary medium, for example, air, to be supplied from the crank case as far as possible free from contamination, more particularly contaminating oil particles, it is common practice to use an oil filter between the crank case and the working space where medium from the crank case is used for supplementary medium for supply to the working space. The construction of such filters and separators is rather involved and when an appreciable amount of dirt has been removed from the medium, the resistance to flow of the supplementary liquid through the filter or separator increases. Further such filters and separators are often comparatively heavy.

The object of the present invention is to provide a hot-gas reciprocating engine or other apparatus in which supplementary medium from the crank casing can be freed from contamination, particularly from contamination by lubricant, in a simple manner.

According to the invention, a hot-gas reciprocating engine or a refrigerator or heat pump operating on the reversed hot-gas reciprocating engine principle, comprising a crank case and means to supply supplementary working medium from the crank case to the working space in which the cycle is performed, is characterized in that in or in direct communication with the crank case provision is made of a screened space having transverse dimensions small compared with its radial dimensions, in which screened space, during the operation of the engine or other apparatus a centrifugal force is set up by the rotation of the crank shaft, a duct for supplying supplementary medium from the crank case to the working space, opening into the central part of the screened space.

Since the centrifugal force is produced, the heavy tates Patent bearings of the crank shaft are not shown.

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particles, for example, oil particles, contained in the screened space move outwards and in the central part of the screened space an atmosphere is produced which is substantially free from contamination. The supplementary medium is taken from this purified atmosphere.

The desired centrifugal flow may be obtained by the screened space being bounded on one side by a transverse wall driven by the crank shaft. The wall may be secured to the crank shaft through the intermediary of a counterweight seated on the crank shaft and be formed by a screen. The wall driven by the crank shaft may have a depression into which projects a duct forsupplying supplementary medium from the crank case to the working space. The advantage is thus obtained that on its path to the duct the supplementary medium travels close to its centre of rotation for a distance so that the separation of, for example, oil particles, is enhanced. The part of the duct extending into the depression may be provided with one or more transverse ridges to prevent, for example, oil particles running down the transverse walls and entering the duct.-

The invention will now be described with reference to one embodiment thereof shown in the accompanying diagrammatic drawing given by way of example and which is a cross sectional view of part of a crank case of a hot-gas reciprocating engine or other apparatus.

The hot-gas engine or other apparatus comprises a crank case having a wall 1. On the left-hand side of the wall 1 is located the enclosed crank space and onthe right-hand side is the ambient atmosphere. A piston 17 is connected to a crankshaft 2 through a rod 18 while a displacer 19 is connected to a crank pin 2a through a rod 20. A working space 21 is located between the displacer 19 and the piston 17 and has one end of a perforated tube 10 connected thereto. The crank case contains a crank shaft 2, having a crank pin 2a. The With the use of a nut 3 and via an arm 4, a counterweight having the shape of a segment of a circle, is secured to the end of the crank shaft 2. To the right-hand surface of the counterweight 5 is secured a screen 6 of sheet material, which has a circular periphery. The outer diameter of the screen 6 is chosen to be such that it fits with a slight amount of radial play in a circular aperture having a peripheral surface 7 and provided in the wall 1 of the crank case. With the use of a cover plate 8, secured to the crank case by means not shown, the aperture is closed. A perforated tube 10 is secured in an aperture 9 provided in the plate 8; the tube 10 is for conveying supplementary medium from the crank case to the working space in which the cycle is performed.

The left-hand end of the tube 10 extends beyond the inner side of the plate 8. The screen 6 has a central depression 11 in which the projecting left-hand end of the tube 10 is accommodated. This projecting end is provided with an annular ridge 12. A gutter 13 is provided between this ridge and the adjacent, thickened part of the tube 10 passing through the plate 8. The spacing between the right-hand side of the screen 6 and the inner side of the plate 8 is small compared with the radial dimension of the space 14 between the screen 6 and the plate 8.

During the operation of the engine or other apparatus, strong eddies occur in the crank case and the air or other gaseous medium contained in the crank case is contaminated with oil. There may be a continuous or a periodical communication between the interior of the crank case and the working space in which the cycle is performed. Owing to pressure differences between these two spaces, medium will flow continuously or periodically through the tube 10 from the crank case to the working space. This medium flows through the circular aperture in the 3 wall 1 of the crank case, via the annular slit 15 between the outer edge of the screen 6 and the surface 7 of the aperture in the wall 1 and the space 14. Owing to the rotating movement of the screen 6- a centrifugal force is-exertedon the medium entering the space 14- through the slit -15 and leaving through the tube 10 which medium movesagainst the direction of this force. Consequently, oil particles contained in the medium will move outwardly in thespace 14, so that there are less oil particles in the medium with decrease in distance fr'om the tube 1%. Since the left-hand end of the tube 10 extends in the depression 11 of the screen fi, medium is rotated rapidly during its travel to the left in this depression before entering the tube 10, so that the separationof, for example, oil particles is enhanced. The medium passing into the tube 10 is substantially free from oil particles. The purification of the medium 'thus obtained will sub stantially always be sufiicient. If, for any reason further purification of the supplementary medium is desired, a

filter or a separator may be housed in the tube 10.

However, this filter or separator may be comparatively small and light.

Any oil which may run down the inner surface of the plate 8 and reach the tube it), is prevented from reaching the aperture in the left-hand end of the tube 16 by the gutter 13 and any oil running downwards on the plate 8 or the screen 6 finds its way via the edge 16 back into the main part of the crank case.

What I claim is:

1. A hot-gas reciprocating engine or a refrigerator or heat pump operating on the reversed hot-gas reciproeating engine principle, comprising a crank case having a cylindrical aperture therein, a crank shaft in said crank case, means to supply supplementary working medium from the crank case to the working space in i which the cycle is performed, a screened space in direct communication with the crank case having small transverse dimensions compared with its radial dimensions, said screened space during the operation of said engine having a centrifugal force set up therein by the rotation of the crank shaft, and a duct for supplying supplementary medium from the crank case to the working space and opening into the central part of the screened space.

2. An engine or other apparatus as claimed in claim 1, characterized in that the screened space is bounded on one side by a transverse wall driven by the crankshaft and seated on the crank shaft.

3. An engine or other apparatus as claimed inclaim 1 further comprising a transverse wall bounding said screened space on one side thereof, a counterweight seated on said crankshaft, said wall being secured to said crankshaft through the intermediary of said counterweight on said crankshaft.

4. An engine or other apparatus as claimed in claim 1 further comprising a transverse wall bounding said screened space on one side thereof, the outer edge of said wall forming a circle which fits with a slight amount of radial play in said cylindrical aperture in the crank case.

5. An engine or other apparatus as 'claimed'in claim 1 further comprising a cover plate for said cylindrical aperture, the inner side of which forms part of said screened space.

6. An engine as claimed in claim 1 further com'pns ing a transverse wall bounding said screened space on one side thereof, said wall being operatively connected to said crankshaft andprovided with a depression into which projects one end of said duct.

7. An engine as claimed in claim 1 further comprising a transverse wall bounding said screened space on one side thereof, said wall being provided with a depression, and said duct having at least one annular ridge thereon positioned transverse to said duct and projecting in said depression.

References Cited in the tile of this patent UNITED STATES PATENTS 2,011,964 Ajam Aug.'20, 1935 2,443,957 Herrington June 22, 1948 2,474,892 Ecabert July 5, 1949 

